Sleet-hammer



1. N. DUNCAN.

SLEET HAMMER..

APPLlcAloN FILED 00114, 1920.

Patanted June 7, 1921.

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l. N. DUNCAN. SLIEET HAMMER. APPLICATloN FlLED'ocT. 14. 1920.

143809544, Patented 111119 7, 192]..

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narran @FFEQEQ JOHN Al.\l'. DUNCAN, OF BOONE, lOl/VA, ASSIG-NOR T0 EIEMSELF, ART F. BRANNBRG,

AND J. C. FLANNERY, ALL OF;BOONE, OWA.

snaar-HAMMER.

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Specification of Letters Patent.

raeentea aune t', rear.

Application filed October 14,` 1920. Serial No. 416,883.

To all whom it may concern Be it known that l, JcirN N. DUNoAma citizen of the United States of America, and resident of Boone, Boone county, lowa,-have .invented a new and useful Sleet-Haminer,

of whichthe following isa specification.

The object of this invention is to provide means, adapted to be carried by a trolley, for removing foreign substances such as ice and sleet from a conductor such as a trolleywire.

A further object of this invention is to provide a pneumatic hammer adapted to be carried by a trolley and arranged to impact with a conductor such as a trolley-wire.

. A further object of this invention is to provide means for mounting .a pneumatic hammer on a trolley.

A further object of this invention is to provide an improved construction Vfor a pneumatic hammer.

My invention consists inthe construction, arrangement and combination of elements hereinafter set forth, pointed out in the claims and illustrated-by the accompanying drawing, in which- Figure 1 is a side elevation showing my device mounted as required for practical use. Fig. 2 is a side elevation, partly in section and on an enlarged scale, showing my device separated fromthe trolley and conductor. .'Fig. 3 is a rear elevation and Fig. 4 is a plan of the devices shown in Fig. 2. Figs. 5 and G are cross-sectionsr onthe indicated lines 55 and 6 6 of Fig. 2.

In the construction andinounting of the devices as shown the nimier'al 10 designates a housing, which is formed with an incliner stem 11 adapted to'be received in and supported by the socket of a trolley-harp, of common form. The housing 10 also is formed with a journal bearing 12 adapted to receive and be supported by a journal or pin 13 carried by the harp 12, which pin is identical with the one usually employed to carry a trolley wheel, thus providing means for substituting the housing and devices carried thereby for the trolley wheel. A concaved shoe or contact member 14 is formed on the upper end of the housing 10, above the bearing 12 and is adapted toslide beneath and in contact with a conductor such as a trolley wire 15. The housing 10 is in circuit between the conductor and the motor and controlling means not shown on a car adapted to carry the harp'by means of arod or pole 16. The housing 10 is formed with a cavity or chamber extendingl entirely through iton a line vsubstantially' parallel with a vertical diameter 0f the bearing 127 which diameter when extended intersects the shoe 14 substantially vmidway of its length. The cavity or chamber in the housing 10 is substantially circular in cross-section and of various diameters to accommodate various elements and have various functions. A cylinder 17 is mounted in the cavity or chamber oftheliousing 10 and at its upper end is fitted to and contacts with an annular portion of the wall of said chamber, while a portion of said cylinder is enlarged in diameter near thefopposite end thereof and is threaded and adaptedto be screwed into a seat'formed in the lower portion of said wall, said seat being of greater diameter than the ttingannular 'portion above mentioned. Ainut 18 is formed on the lower end of the cylinder 17'to facilitate placing and removal thereof. l'llhe cavity or chamber in the housing 10 has its greatest diameter surrounding the cylinder 17 between'the fitted portion and the threaded seat in its wall, thus forming an Vair chamber 19, which is in constantcommunication vat its lower end through'ports v2O with the interior of the cylinder and hasl a like communication at its upper -end through ports 21. The cylinder 17 is tubular and the interior diameter thereof is slightlyfless at its upper end than throughout the major portion vof its length. A hammer 22 yis fitted -within and mountedloosely relative to the cylinder 17, the upper end of the'hammer fitting the restricted portion of the bore of the cylinder and also fitting a hole 23 alining therewith in the top ofthe housing, said hole forming the upper end of the cavity or chamber in the housing, thev lower end portion of said hammer materially lessV than half itslengthtting the larger or body portion of the bore of the cylinder,lthus forniing or producing an air chamber 24 within the cylinder and surrounding the central portion of the hammer. A plug 25 is screwed into the lower end of the cylinder 17 and abuts the lower end of the hammer 22 and the inner end of the kplug closes the bore of the cylinder and constitutes a pressure-head in the operation ofthe device. The plug 25 extends across the ports 2O in ioo the cylinder and is formed with an annular peripheral groove 26 communicating with said ports and also is formed with radial ports 27 communicating with said groove. .The plug 25 also is formed with an axial bore 28 throughout part of its length and communicating at its inner (upper) end with the ports 27, the outer end of said bore being threaded to receive a coupling 29 whereby an air hose 30 may be connected to the plug. The hose 30 may be supplied in any desired manner such as by a pump or tank carried on the car above mentioned, When the hammer is at rest, as shown, the upper end thereof is substantially flush with the upper end of the cylinder and the lower end of said hammer is in Contact with the upper end of the plug 25. r1`he hammer 22 is formed with a central bore 31 throughoutA the major portion of'its length and opening through the lower end thereof to the pressure-head of the plug 25. Radial ports 32 are formed in the hammer 22 and communicate at times between the bore 31 and the air-chamber 24. The diameter of the cavity or chamber in the housing 10 is enlarged adjacent to the upper end of the cylinder 17, thus forming an exhaust chamber 33, intersected and traversed at times by the hammer 22, and ports 34 are formed in the upper end of the housing and communicate betweensaid chamber and the atmosphere externally of the housing.

When it is desired to remove foreign substances, such as sleet and ice, from the conductor 15, a car equipped as shown and described is run over the line, the shoe 14 taking current from the conductor and the hammer being supplied with compressed air through the hose 30 and its connections. rlhe air enters the housing through the bore 28, ports 27, annular groove 26, and ports 20 and lls the chamber 19 around the cylinder. Air passes from the chamber 19 through the ports 21, lls the chamber 24, passes through the ports 32 and bore 31 and expands within the hammer. The action of the compressed air on the pressurehead of the plug 25, reacting on the interior of the hammer and particularly on the head of the bore, forces the hammer outwardly as indicated by dotted lines in Fig. 2, into forcible contact or impact with the conductor 15. In its outward movement, the hammer traverses the exhaust chamber 33 and hole 23; the inlet ports 32 of the hammer pass out of register with the cham ber 24, thus cutting off the entrance of compressed air to the hammer; and the ports 32 in the hammer come into register with the chamber 33, which is open to the atmosphere through the ports 34, thus permitting relief in the hammer. ln its outward move-l ment a shoulder 35 on the hammer traverses the chamber 24 to a pointbeyond theV ports 2l and cuts off communication between the chambers 19 and 24 and, further, compresses air and forms a cushion thereof in the upper end portion of the chamber 24. This cushion of air in the upper end portion of the chamber 24 acts as a brake for the outward movement of the hammer and provides l reactionary impulse sufficient to return the hammer to its normal position of rest on the pressure head of the plug 25. lt will be observed that when the hamm-er is lifted from the pressure head compressed air may act between the lower end of the Vhammer and said head directly until the inlet is closed by travel of the ports 32 and thereafter by expansion. Thus the maximum force of the air supply is employed, to move the hammer outwardly and cause it repeatedly to impact or strike the conductor to the end of jarring loose and removing ice and sleet therefrom.

It is to be understood that the hammer may be employed and operated in other work when desired.

l claim as my invention- 1. A sleet hammer comprising a housing removably and replaceably mounted on and adapted to be carried by a trolley harp, means on said housing adapted for electrical contact with a conductor, a pneumatic hammer mounted in said housing and means for applying air within said housing for the operation of said hammer.

2. ln a sleet hammer the combination with Y a trolley and a housing;` adapted to collect current from a conductor, of a pneumatic hammer carried by said housing and arranged for impact with said conductor.

3. In a sleet hammer, the combination of a housing adapted to be carried by a trolley pole, a shoe on said housing adapted to engage a conductor slidingly and a pneumatic hammer carried by said housing and adapted to impact said conductor.

Signed at Des Moines, in the county of Polk and State or" lowa, this 20th day of September, 1920. i

JOHN N. DUNCAN. 

